Is it possible to hide some shapes in a loaded scene?

[wylighting]

Hi~

I want to randomly remove (hide) some shapes in a scene to render many image samples, but I am not sure the best practice to achieve this. One possible way is to modify the scene description and use 'mi.load_dict' for each data sample, but it will cause the duplicated loading process which is slow. So, it is possible to achieve this in a loaded scene directly? For example, can I specify a shape to be excluded in the ray intersection process?

[njroussel]

Hi @swordigo1995

Currently there is no support for something like this. There are two possible workarounds though:

1. Use the mask BSDF to make the shape transparent. It is very likely that this will producer noisier images as shadow rays will still intersect the shape.
2. Move the shapes far away from your scene by updating their to_world parameter. This would re-build acceleration structure for the ray-shape intersections, depending on your scene this shouldn't bee too slow.

[wylighting]

Thanks!